Panel with a sound insulation layer and production method

ABSTRACT

The invention relates to a method for applying to a flooring panel a layer designed to reduce the footfall sound on the floor, and a panel of this kind. With the prior art, it is disadvantageous that the sound-insulation layer is glued onto the laminate panel in a subsequent manufacturing stage. Accordingly, the panel is initially manufactured by pressing with the associated gluing of layers and/or papers. The sound-insulation layer is glued in place in a subsequent operational stage. PVA-glues, thermoplastics or wood glues may be used, for example, to attach the sound-insulation layer. In the manufacture of a panel with a carrier board, decorative paper, counteracting paper and/or a wood veneer, an additional layer, preferably in the form of a sheet or a roll, is provided. The material of this roll or sheet product is designed to provide the desired sound-insulation properties as described above and/or provides these properties when a panel is being walked over. The roll or sheet product is placed in a press and pressed together with the other components at a temperature of at least 100° C.

[0001] The invention relates to a method for applying to a flooringpanel a layer designed to reduce the footfall sound on the floor, and apanel of this kind.

[0002] In the context of flooring, panels in the form of laminatedflooring or parquet flooring are already known. A laminated flooringpanel consists of a so-called carrier board, which is generallymanufactured from HDF, MDF or chipboard. A so-called decorative paperand another layer, which ensures adequate resistance to abrasion on theupper surface, are generally disposed above the carrier board. Thedecorative paper may, however, already be designed to beabrasion-resistant. A so-called counteracting paper is disposed beneaththe carrier board.

[0003] In particular, the papers are impregnated with aminoplastics,especially, with urea resins and/or melamine resins. Such resins willsoften and harden again, if the papers are pressed with the carrierboard in a press under the influence of temperature and pressure.

[0004] The decorative paper ensures the desired visual appearance of theflooring formed from the panels. The counteracting paper is provided toensure that the carrier board and/or the panel are not distorted duringthe pressing of the layers and/or papers.

[0005] Parquet panels differ from laminate, in particular, withreference to their surface. The desired visual effect is achieved withwood instead of with a printed paper. A parquet floor is made of solidwood, but may also provide a carrier board made from HDF, MDF orchipboard. In this case, a wooden veneer or paper is then applied to theupper surface. A special wood or paper layer is applied to the undersideas a counteracting layer.

[0006] If the panels are laid on an under-floor, a relatively loudfootfall sound occurs when the floor is walked over. To prevent thedevelopment of such sound, the prior art provides a so-calledfootfall-sound-insulation. This is a layer with sound-damping and/orsound-absorbing properties applied beneath a panel. Additionally, or asan alternative, the layer may bring about a shift in the frequency andamplitude of the sound produced, which is then subjectively perceived asless disturbing.

[0007] The layer providing footfall insulation will be referred to ingeneral below as the “sound-insulation layer”.

[0008] Sound-insulation layers are designed, in particular, as follows:

[0009] The sound-insulation layer is generally resiliently deformable bycontrast with the panel defined above. A layer of this kind may consist,for example, of recycled polyurethane material, rubber, cork, foam,thermoplastic materials, fibre matting or LDF (low density material).The density is generally around 200 to 1000 kg/m³. Alternatively, aso-called heavy foil can be used as a sound-insulation layer. This ischaracterised by a weight of 1000 to 5000 g/m².

[0010] A heavy foil glued to the laminate ensures good contact with theunder-floor, which improves application to the surface disposed beneaththereby enhancing the perception of sound when walking on the floor. Atypical heavy foil consists of polyethylene with fillers.

[0011] With the prior art, it is disadvantageous that thesound-insulation layer is glued onto the laminate panel in a subsequentmanufacturing stage. Accordingly, the panel is initially manufactured bypressing with the associated gluing of layers and/or papers. Thesound-insulation layer is glued in place in a subsequent operationalstage. PVA-glues, thermoplastics or wood glues may be used, for example,to attach the sound-insulation layer.

[0012] Retrospective gluing and the associated additional operationalstage not only makes the manufacturing process more expensive, but theedge seal is also relatively poor. If a sound-insulation layer isattached in a separate operational stage, it is hardly possible toachieve a successful flush edge seal. In general, therefore, there is aregion, beneath the panel, which is without a sound-insulation layer,because a flush seal is difficult to achieve in practice and is unlikelyto be of good quality. Accordingly, the desired effect of thesound-insulation layer is impaired. Since this region is generallyadjacent to the tongues and grooves of the panel, the mechanicalstresses on these locking elements are particularly large when the flooris walked over. Moreover, there is a risk, that the sound-insulationlayer can become detached from the panel during subsequent processingstages or during floor laying.

[0013] Furthermore, a thermoplastic glue provides the disadvantage thatit does not bond the sound-insulation layer particularly firmly to thepanel, and the sound-insulation layer can easily become detached fromthe panel. This leads to in handling problems and disadvantages inproduction, for example, when the connecting elements are cut to size.

[0014] If the sound-insulation layers are easily detached from thepanel, this creates problems whenever the panels need to be shiftedduring laying, because the sound-insulation layer could become detachedfrom the panel during laying. Providing a method and an associatedpanel, wherein the sound-insulation layer is connected to the panel inan improved manner, wherein the edge seals are improved and whereinproduction costs are more favourable, is a desirable objective.

[0015] The adhesive materials used may be associated with environmentalproblems. For example, the adhesives may contain solvents, which pollutethe environment. This leads to problems relating to the disposal of theadhesives. Moreover, the adhesive is an additional component required inthe production process. Avoiding the use of an additional adhesive forattaching a sound-insulation layer to a panel is therefore alsodesirable.

[0016] The object of the invention is to provide a cost-favourablemethod together with an associated panel, which, by comparison with theprior art, provides improved properties in a footfall and roomsound-insulation layer.

[0017] The object of the invention is achieved by a method with thefeatures of claim 1 and by a panel with the features of the subsidiaryclaim. Advantageous embodiments are specified in the dependent claims.

[0018] According to the invention, in the manufacture of a panel with acarrier board, decorative paper, counteracting paper and/or a woodveneer, an additional layer, preferably in the form of a sheet or aroll, is provided. The material of this roll or sheet product isdesigned to provide the desired sound-insulation properties as describedabove and/or provides these properties when a panel is being walkedover. The roll or sheet product is placed in a press and pressedtogether with the other components at a temperature of at least 100° C.Higher temperatures are preferably provided during pressing, inparticular, temperatures above 120° C. The temperatures are typicallyabove 200° C., but preferably 230° C. to 250° C., in order to achieveshort pressing times. Short pressing times allow the panels to bemanufactured more rapidly, ensuring that the method is cost favourable.

[0019] The sheet or roll product must be suitably temperature resistant.If pressing takes place at 200° C., the material, from which thesound-insulation layer is made, must be able to withstand the selectedtemperature.

[0020] Selecting the appropriate materials in dependence upon acorresponding pressing temperature, in order to achieve acost-favourable manufacturing process, can be left to a person skilledin the art.

[0021] In the manufacture of a laminate panel, the counteracting paperis impregnated with an aminoplastic. During pressing, the aminoplasticmaterial bonds the sound-insulation layer to the panel.

[0022] The bond between the sound-insulation layer and the panel isconsiderably more stable by comparison with the prior art.

[0023] The manufacturing process is also more cost favourable, becauseone operational stage has been omitted. Additional adhesives are notrequired, which also leads to cost advantages. Furthermore, the methodis environmentally friendly, because adhesives, which must beadditionally disposed of, are not required. Solvents present in theadhesives are also avoided.

[0024] According to experience, after the manufacture of a large-formatpanel, the panels are sawn into panels of, for example, 1.40 m×0.20 m,and the locking elements, such as tongues and grooves are milled intothe panels. A flush edge seal is achieved between the panel and thesound-insulation layer, and accordingly, in this context, thedisadvantages named above are avoided.

[0025] Since the bond between the sound-insulation layer and the panelis very strong, the milling stage can be carried out without difficulty.With the prior art, this process presented difficulties, because thebond between the panel and the footfall sound-insulation layer wasrelatively unstable.

[0026] If the sound-insulation layer is to be connected to a parquetpanel, a short-cycle press is used for this process. To provide theaminoplastic, a paper can be placed between the lowest layer of thepanel and the sound-insulation layer. In this case, the paper may beimpregnated or otherwise provided with the aminoplastic.

[0027] In one embodiment of the invention, a recycled polyurethanematerial is used, and the sound-insulation layer is formed from thismaterial. The material is cost favourable and provides very goodsound-insulation properties. It is obtained from the recycling industryand is therefore environmentally compatible.

[0028] In this context, the sound-insulation layer should be at least0.5 mm thick in order to achieve good sound-insulation properties, whichare acceptable to the consumer. In practice, the layer made fromrecycled polyurethane material can be up to 5 mm thick. If thesound-insulation layer is very thick, noticeable disadvantages occurwith reference to thermal conductivity. Good thermal conductivity isrelevant if under-floor heating is to be installed or used. Anexcessively thick laminate floor is also undesirable, because of theassociated large structural height after laying. This is disadvantageousto the consumer, for example, because doors may have to be adapted, asoccurs routinely, particularly in the context of refurbishment.

[0029] Melamine resin and/or urea resin and/or mixtures thereof arepreferred as the aminoplastics. These are resins, which are typicallyused in decorative papers and counteracting papers. If these resins areused, no additional material components need to be provided for themanufacture of the product.

[0030] The pressure applied in the press is typically between 5 and 70kPa. The sound-insulation layer is generally compressed during thisprocess. When using polyurethane (PUR), the layer is typicallycompressed, for example, from 1.2 mm to 0.5 mm. However, because of theconservation of mass, the sound-insulation properties are notsignificantly changed.

[0031] Recycled polyurethane material, for example, with a densitybetween 110 kg/m³ and 750 kg/m³ may be used as a starting material.

[0032] The product manufactured according to the invention differs fromthe prior art particularly in that the bond between a panel and thesound-insulation layer is achieved with an aminoplastic. In particular,the bond is achieved on the basis of aminoplastics, which are also usedin the manufacture of a panel. This is advantageous because it avoidsthe use of additional materials.

[0033] In a further embodiment of the invention, as an alternative torecycled polyurethane material, a material, from which a heavy foil ismanufactured, may be used. Polyethylene with fillers is preferred inthis context.

[0034] Experiments have shown that the named materials, recycledpolyurethane material and polyethylene with the fillers, achieveparticularly good sound-insulation properties. Moreover, these materialscan be processed without difficulty and attached to a laminate orparquet flooring panel.

[0035] In manufacturing, products on a roll are used by preference, sothat the panels can be pressed using double-band press. Otherwise ashort-cycle press would have to be used, which would significantlyincrease manufacturing costs, because short pressing times cannot berealised.

[0036] With the method according to the invention, a panel ismanufactured, in which a layer is bonded beneath the panel using anaminoplastic. Because sawing and milling are carried out at a subsequentstage, the product is essentially characterised by its very good edgeseal. Accordingly, no gap is left between the underside of the panel andthe sound-insulation layer. This means that the flush edge seal is anadditional essential feature of the product manufactured according tothe method.

[0037] The sound-insulation layer terminates flush with the panel, inparticular, at the position where sawing or milling has been carriedout. For example, the flush seal can also be provided with a groove,which has been milled into the underside of the panel, for example, foruse in a non-glued connection between panels.

[0038] A visible offset between the sound-insulation layer and theflooring panel does not therefore occur, unless it is created inanother, subsequent operational stage.

[0039] The selected materials, recycled polyurethane material andpolyethylene with fillers, are heat-resistant, so that they can bepressed under the influence of heat. They are also particularly suitablefor this reason.

[0040] In the case of a laminate, the thickness of a panel is typically5 to 14 mm. With parquet flooring panels, the thickness is typicallyapproximately 10 to 20 mm. The sound-insulation layer on the underside,which may be very thin, is added to this.

[0041] The sound-insulation layer is preferably thinner than the panel,in particular, thinner than the carrier board.

[0042] The invention will now be described in greater detail withreference to the exemplary embodiment shown in the drawing.

[0043] The drawing shows a cross-section of a laminate panel, which hasbeen manufactured from a carrier board 1, a decorative paper 2, acounteracting paper 3 and an abrasion-resistant layer 4. The carrierboard consists of MDF/HDF (but other materials are possible). Thismaterial is made from wood fibres, which are first provided with glueand then pressed in a press to form a board. The decorative paper 2 isfirst attached to the carrier board 1, and the abrasion-resistant layer4 is attached above this. The counteracting paper 3 is attached beneaththe carrier board 1. The paper layers and the abrasion-resistant layerare initially provided with a mixture of a melamine resin and/or urearesin. Under the influence of heat and pressure, the resins aresoftened. A strong bond between the various layers is achieved throughthe subsequent hardening.

[0044] By way of difference from the prior art, according to the presentinvention, a sound-insulation layer 5 was additionally pressed togetherwith the other layers named above. The sound-insulation layer, in thiscase, consists of polyurethane (PUR). The initial layer thickness was1.2 mm. As a result of compression of the various layers, this thicknessis reduced to 0.5 mm. The sound-insulation layer 5 is bonded to thecounteracting paper 3 by means of the resins used.

[0045] After manufacturing the layered composite material, a groove 6and a tongue 7 were milled into the sides of the panel. A groove 8 isprovided in the underside of the panel (if required).

[0046] As a result of the manufacturing method, the transition from thesound-insulation layer 5 to the panel is flush. This applies to thelateral limits of the panel and also to the transitions which occurrelative to the groove 8.

[0047] Metal plates, which connect two panels 1 together in thehorizontal direction, can be inserted into the groove 8 of one panel andthe corresponding groove 8 of another panel during floor laying.Accordingly, a groove 8 is allocated to each tongue and each groove. Forreasons of clarity, only one groove 8 has been shown in the drawing. Ifthe panel had been drawn in its entirety, another groove 8, allocated tothe tongue 7, would be visible in mirror-image reversal.

1. Method for manufacturing a panel with an attached sound-insulation layer, wherein several layers are pressed in a press under the influence of pressure and heat, said individual layers consisting of wood, wooden material or paper, and at least one or more layers being provided with an aminoplastic, wherein said layers are pressed together with the sound-insulation layer, and said panel is provided with locking elements comprising tongues and grooves, after pressing.
 2. Method for manufacturing a panel according to claim 1, wherein said sound-insulation layer consists of a resiliently deformable material.
 3. Method for manufacturing a panel according to claim 1, wherein said sound-insulation layer consists of recycled polyurethane material, rubber, cork, foam, thermoplastic materials, fibre matting, LDF or polyethylene.
 4. Method for manufacturing a panel according to claim 1, wherein said sound-insulation layer provides a density from 20 to 2500 kg/m³.
 5. Method for manufacturing a panel according to claim 1, wherein a carrier board is used as the layer to be pressed, and the sound-insulation layer is preferably thinner than said carrier board.
 6. Method for manufacturing a panel according to, wherein a carrier board, which consists of HDF, MDF, chipboard or wood, is used as said layer to be pressed.
 7. Method for manufacturing a panel according to claim 1, wherein papers impregnated in an aminoplastic are used as said layers to be pressed.
 8. Method for manufacturing a panel according to claim 1, wherein a carrier board and a sound-insulation layer are pressed with a paper impregnated with an aminoplastic and disposed between them.
 9. Method for manufacturing a panel according to claim 1, wherein a melamine resin and/or a urea resin is used as said aminoplastic.
 10. Method for manufacturing a panel according to claim 1, wherein at least one layer consisting of wood, which preferably forms an upper layer in the layer system to be pressed, is provided.
 11. Method for manufacturing a panel according to claim 1, wherein said sound-insulation layer consists of a material, which is temperature-resistant above 100° C., preferably above 200° C.
 12. Method for manufacturing a panel according to claim 1, wherein said panel manufactured in the above manner is sawn after pressing.
 13. Panel, capable of being manufactured using a method according to claim 1, wherein a sound-insulation layer is attached to the underside of said panel by means of an aminoplastic, and said panel provides locking elements comprising lateral tongues and grooves.
 14. Panel according to claim 13, wherein said sound-insulation layer consists of a resiliently deformable material.
 15. Panel according to claim 13, wherein said sound-insulation layer consists of recycled polyurethane material, rubber, cork, foam, thermoplastic materials, fibre matting, LDF or polyethylene.
 16. Panel according to claim 13, wherein said sound-insulation layer provides a density from 20 to 2500 kg/m³.
 17. Panel according to claim 13, wherein said panel provides a carrier board, and said sound-insulation layer is thinner than the carrier board.
 18. Panel according to claim 13, wherein said panel provides a carrier board, which consists of HDF, MDF, chipboard or wood, and a decorative paper or a wood veneer is applied above said carrier board.
 19. Panel according to claim 13, wherein a paper provided with an aminoplastic is adjacent to said sound-insulation layer.
 20. Panel according to claim 13, wherein a melamine resin and/or a urea resin is used as the aminoplastic.
 21. Panel according to claim 13, wherein at least one layer is provided consisting of wood, to form an upper layer in said layer system, which forms said panel.
 22. Panel according to claim 13, wherein said sound-insulation layer consists of a material, which is temperature-resistant above 100° C., preferably above 200° C.
 23. Panel according to claim 13, wherein said sound-insulation layer terminates flush with said panel at said sides.
 24. Panel according to claim 13, wherein said panel is 5 to 20 mm thick, and said sound-insulation layer is up to 5 mm thick.
 25. Panel according to claim 13, wherein at least one groove is milled into said panel from below, and said sound-insulation layer meets the groove at both sides in a flush manner. 